Visiting South Falls is very easy. It is located near the South Falls Lodge.
A short walk from the parking area takes you to nice views of the falls from the rim.
Even better views can be had from the Canyon Trail, aka the Trail of Ten Falls.
This trail descends down into the canyon and behind South Falls, and then down stream
past and behind Lower South Falls, and then works its way
up the north creek passing 8 more falls including
Middle North Falls, North Falls,
both of which the trail goes behind, and
ending at Upper North Falls.